Genome size variation in Melipona species (Hymenoptera: Apidae) and sub-grouping by their DNA content

The stingless bees of the genus Melipona comprise a group with approximately 40 Neotropical species. Despite their ecological and economic importance, the size of the genomes of these species remains poorly known. Thus, the present study measured the DNA content of 15 Melipona species. The mean genome size (1C) of the females ranged from 0.27 pg to 1.38 pg, with increments of, approximately, 0.12 pg. It was possible to recognize two groups of species: the first presented relatively low DNA content (average = 0.29 pg), while the second showed high DNA content (average = 0.98 pg). This result corroborates the cytogenetic classification of these species into two groups, one of them comprising species with a low heterochromatin content (<50%), and the other species with high heterochromatin content (>50%). Amongst the groups with low and high DNA content, there was no significant correlation between the DNA content and the size of the bees. The data obtained may aid in the selection of species which are suitable for sequencing projects, besides providing an overview of the diversity in the genome size of the Melipona genus.